I thought of an alternative way a while back, when I thought about how you created your avatar:
1. Render some clouds
2. Create a new layer with blending mode; Overlay and put some colour over those clouds.
3. Merge the two layers together.
4. Filter > Pixelate > Mosaic
5. Create your ‘face’ shape
6. Transform > Warp the colour layer to get some shape over the face.
7. Add detail like shading.

Never tried it before though, but I think that’ll be of a shorter timespan than 4 hours

Thanks guys for your nice comments! It’s super awesome you like it, I hope I win that avatar competition – I was a little surprised by the number of votes for mine avatar, thanks a lot again and cheers!

@Mark&Jason: Thanks for your offers, but sorry guys, I don’t enjoy writing anything and if some day I will, I probably set my own blog or something – nothing personal against you!

@Daan: Your steps are okay too, but I wanted to have complete control over every “pixel” so I had to cut the main shape manually. Plus warping the mozaic layer can loss some quality I guess. And 4 hours for a logo is nothing At least I am slow in this and this was quite success for me lol.